Alwindtour

windtour  时间:2021-05-25  阅读:()
TheImportantPeakIndexoftheRegistryofMassSpectralDataFredW.
McLaffertyandDouglasB.
StaufferJohnWileyandSons,Inc.
,NewYork[Phone:(800)526-5368;Fax:(201)302-2300],3Volumes,4,057pp.
,ISBN#0-471-55270-4,1991,$750.
00BookreviewbyK.
B.
Tomer,NationalInstituteofEnvironmentalHealthSciences,P.
O.
Box12233,ResearchTrianglePark,NC27709Thisisathree-volumesetofbookscontainingatabu-lationofthesix"mostimportant"peaksofthe136,141differentmassspectraof115,917compoundscontainedintheWiley/NBSRegistryofMassSpectralData.
Spec-traarelistedbythemass-to-chargeratioofeachofthethree"mostimportant"peaksinamannersimilartothatoftheEightPeakIndex.
WhatdifferentiatesthesevolumesfromitsparentpublicationandfromtheEightPeakIndexisthatthepeakslistedhavebeenchosenonthebasisoftheirstatisticalimportanceratherthanjustontheirrelativeabundance.
Todeterminethestatisticalimportanceofthepeaks,theauthorshaveusedthesamealgorithmsastheyhaveemployedintheir"ProbabilityBasedMatching"system.
Thisap-proachreducestherelianceonrelativelycommonions,suchasrn/z43,foridentification.
Todeterminethe"mostimportant"ions,boththestatisticalimportanceofthemassaswellastherela-tiveabundanceisconsidered.
Thestatisticalimpor-tanceoruniqueness,U,ofanionisbasedontheinverseoftheprobabilityofoccurrenceofthepeakintheRegistrydatabase.
Thus,anionsuchasm/z43,whichhasahighprobabilityofoccurrence,willhavealow(zero)UvaluewhileionswithlowprobabilityofoccurrenceswillhavehighUvalues.
Therelativeabundanceofamass,A,isfactoredinonthebasisoftheinverseoftheprobabilityofoccurrenceofanionwiththatrelativeabundance.
Thus,ionsofhighrela-tiveabundanceoccurmuchlessfrequentlythandoionsoflowrelativeabundanceand,therefore,receiveahigherAvalue.
TheionswiththehighestA+Uvaluesaredefinedasthemostimportantions.
EachpageofthevolumehasalistingoftheUandAvaluestobeusedindeterminingapeak'simportance.
Al-though,atfirstglance,itappearsthatthisapproachmaybedifficulttogetusedto,the"importantpeaks"tendtobethosepeaksthatatrainedmassspec-trometristwouldpick.
Ifoundthesystemtoberela-tivelysimpletouseafteronlyafewapplications.
Theutilityofthevolumes,however,mustrestonhowwellunknownscanbeidentified.
Itestedthisbytryingtoidentifyanumberofspectrathatwereinmyfiles,includingsomethathavebeenreportedandsomethathavenotappearedintheliteratureoradata-base.
Theidentityofcompoundswhosespectra1993AmericanSocietyforMassSpectrometry1044-0305/93/$5.
00BOOKREVIEWShavebeenpublishedwereaccurately,rapidly,andeasilyidentified.
Notsurprisingly,compoundswhosespectrahavenotbeenreportedweremoredifficulttoidentify.
Insomecases,theidentitiesofcompoundswhosespectracontainedsimilar"mostimportant"ionswereoflittlehelpinidentifyingtheunknown.
Inothercases,theseidentitieswerequiteusefulinestablishingthegeneralclassofcompound.
Interestingly,the"mostimportant"peaksofsteroidmetabolitesoftenledtolistingsinwhichsteroidspredominated.
Insummary,thisindexisausefuladjuncttotheRegistrydatabase,especiallyasthelocationintheRegistrydatabaseisgivenforthefullspectrumofeachlisting.
Itwillbeanimportanttoolfortheidentifica-tionofunknownsbasedontheirmassspectraandcanbequiteusefulininterpretingthespectraoftrueunknowns.
Althoughthesetmaybetooexpensiveforindividualpurchasers,Iexpectthatthesevolumeswillbefoundinmostlaboratoriesthatdealwiththeinter-pretationLfspectra.
MassSpectrometryE.
ConstantinandA.
SchnellEllisHorwoodLtd.
,Chichester,UK[Phone:0442231555;Fax:0442275115].
184pp.
,ISBN#0-13-555525-6[hardcover,$79.
95],#0-13-553363-5[paperback$29.
951,1991.
BookreviewbyM.
M.
Bursey,DepartmentofChemistry,CB#3290VenableHall,UniversityofNorthCarolinaatChapelHillChapelHill,NC27599-3290ThistextbookisatranslationbyDr.
M.
H.
ChalmersofaFrenchtextfirstpublishedin1986.
Itincludesawhirlwindtourofthesubject.
Itmightbeconsideredasatextforabriefcourseonthemajortopicsinmassspectrometry,oritmightbeusedbysomeonetrainedinanotherfieldofthechemicalsciencesasawaytoreadintoourfield.
Thesubjectsofthechaptersaremassspectrometry;methodsofionization;classicalelectronimpactionizationsource;methodsforsampleintroduction;themassanalyser;methodsofdisplay,recording,andprocessingofsignals;typesofions,peaks,andmassspectra;nominalmassandexactmass;analysisofcarbonisotopes;metastableions;ion-moleculereactions;ionclusters;specialsources;appli-cationsofmassspectrometryinatmosphericinvestiga-tions;theoryofspectra;ionfragmentationmecha-nisms;isotopicanalysis;andrecentdevelopments.
Theaveragechapterisninepageslong.
Asacoursetextbook,itistoocondensed.
(Interpre-tationofmassspectraiscoveredinhalfapage,forexample.
)However,asitflitsfromtopictotopic,itspendsjustenoughtimeonmosttopicstomakestu-JAmSocMassSpectrom1993,4,82-83BOOKREVIEWS83dentsawareoftheexistenceofongoingintellectualactivityineacharea.
Inadditiontothereferencescitedforeachchapter,suggestionsforfurtherreadingaregivenforthelasttenchapters,andthereareaone-pagegenerallistofreviewsandarticlesofinterestandatwo-pagegeneralbibliography.
Tomyknowledgethisbookisuniqueasanintro-ductiontosomanytopicsforasurveycourse.
Soitmightbeused,forexample,inconjunctionwithamorethoroughintroductiontospectralinterpretation,togetherwithdistributednotestofillouttheteacher'sownpreferencesfordetailedconsideration.
Thesectiononspecialsourceswouldhavetobeamplifiedonthedevelopmentsinmatrix-assistedlaserdesorptionandinelectrospraythathaveoccurredsince1986,forex-ample.
Therearejustenoughtypographicalerrorstono-tice.

ucloud香港服务器优惠活动:香港2核4G云服务器低至358元/年,968元/3年

ucloud香港服务器优惠降价活动开始了!此前,ucloud官方全球云大促活动的香港云服务器一度上涨至2核4G配置752元/年,2031元/3年。让很多想购买ucloud香港云服务器的新用户望而却步!不过,目前,ucloud官方下调了香港服务器价格,此前2核4G香港云服务器752元/年,现在降至358元/年,968元/3年,价格降了快一半了!UCloud活动路子和阿里云、腾讯云不同,活动一步到位,...

HostKvm5.95美元起,香港、韩国可选

HostKvm发布了夏季特别促销活动,针对香港国际/韩国机房VPS主机提供7折优惠码,其他机房全场8折,优惠后2GB内存套餐月付仅5.95美元起。这是一家成立于2013年的国外主机服务商,主要提供基于KVM架构的VPS主机,可选数据中心包括日本、新加坡、韩国、美国、中国香港等多个地区机房,均为国内直连或优化线路,延迟较低,适合建站或者远程办公等。下面分享几款香港VPS和韩国VPS的配置和价格信息。...

创梦网络-江苏宿迁BGP云服务器100G高防资源,全程ceph集群存储,安全可靠,数据有保证,防护真实,现在购买7折促销,续费同价!

官方网站:点击访问创梦网络宿迁BGP高防活动方案:机房CPU内存硬盘带宽IP防护流量原价活动价开通方式宿迁BGP4vCPU4G40G+50G20Mbps1个100G不限流量299元/月 209.3元/月点击自助购买成都电信优化线路8vCPU8G40G+50G20Mbps1个100G不限流量399元/月 279.3元/月点击自助购买成都电信优化线路8vCPU16G40G+50G2...

windtour为你推荐
LadenchromeSAProute游戏ios2.3ios5勒索病毒win7补丁由于电脑没连接网络,所以成功躲过了勒索病毒,但最近要联网,要提前装什么补丁吗?我电脑断网好久了win7telnetwindows7旗舰版中telnet在哪x-routerx-arcsinx的等价无穷小是什么?联通iphone4联通iphone4怎么样,好不好用?联通iphone4联通iphone4好用吗win7关闭135端口win7系统怎么关闭135端口?网上很多方法都不好用!
apache虚拟主机 com域名注册1元 韩国vps俄罗斯美女 欧洲欧洲vps xenvps 域名服务器上存放着internet主机的 linode代购 网络星期一 evssl证书 北京双线机房 老左来了 中国电信测网速 微软服务器操作系统 免费邮件服务器 域名与空间 免费asp空间申请 cdn服务 winserver2008 cdn加速技术 magento主机 更多